Airbag control unit with part number AB39-14B321-DJ

What does the airbag control unit AB39-14B321-DJ do?

The airbag control unit AB39-14B321-DJ controls the restraint system (SRS) of Ford. It evaluates the crash sensors and, in a collision, decides within a split second which airbags and seatbelt pretensioners are triggered. After an accident it stores crash data and locks itself.

Outside an accident the unit continuously checks the system for faults. Every deviation is recorded in the fault memory and shown on the instrument cluster.

It checks sensors, ignition circuits and the warning display together.

Why does the control unit AB39-14B321-DJ fail?

Stored crash data from an earlier accident is the most common cause, even if no airbag was deployed in it. Ageing electronic components, cold solder joints, moisture and corrosion at plug connections, and voltage spikes are also possible. A standard diagnostic tool cannot erase this crash data on the control unit AB39-14B321-DJ.

Crash data document what the control unit recorded during the event. They stay in memory regardless of how much of the accident is still visible on the vehicle.

Ageing components and cold solder joints lead to fluctuating signals. Moisture and corrosion at plugs worsen the contact, and voltage spikes arise when the battery is weak or when jump-leads are connected.

How can you tell that the AB39-14B321-DJ is defective?

If the airbag warning light in the instrument cluster lights up permanently or intermittently, this indicates a defect. Also possible are a fault message in the instrument cluster, a diagnostic tool with no connection to the control unit AB39-14B321-DJ, or a fault memory that cannot be cleared. In that case, airbags and seatbelt pretensioners may possibly not deploy in an emergency.

The warning light is the most direct indication the vehicle gives. It reports the fault as soon as the control unit has detected it.

A fault message in the instrument cluster must not be ignored either: it shows that the restraint system is not fully operational.

Which vehicles is the AB39-14B321-DJ fitted in?

The control unit AB39-14B321-DJ was fitted in the following vehicles of Ford: Ford Ranger 3 (2011-2015), 3 1st Facelift (2016-2019) and 3 2nd Facelift (2019-2023). The assignment applies to this exact part number.

The following list shows the vehicles known to us for this number.

• Ford Ranger 3 (2011-2015)
• Ford Ranger 3 1st Facelift (2016-2019)
• Ford Ranger 3 2nd Facelift (2019-2023)

Comparing the number on the label with this page only ensures that it is the correct unit. The cause is established by the fault memory, which you should have read out before removal, because only it shows whether the control unit is defective or a plug or cable is the cause.

For the same vehicles, we also repair control units with the part numbers AB3914B321CF, KB3T-14B321-BD.

How does the repair of the AB39-14B321-DJ work?

First have the fault memory read out and attach the log. Then disconnect the battery and remove the control unit AB39-14B321-DJ. Create a repair order online and send in the unit, well packed.

Airbag24 checks the unit on the test bench, repairs defective components, erases stored crash data and carries out a function test. Processing at Airbag24 usually takes 3–4 working days, after which your own unit is returned.

Our repairs come with 2 years' statutory liability for defects. The repaired control unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.

How does the control unit AB39-14B321-DJ get to Airbag24?

You send the control unit AB39-14B321-DJ as a parcel, or you book a UPS collection for an extra charge. Airbag24 returns the repaired unit to you by UPS.

The printed repair order goes into the parcel, and the control unit AB39-14B321-DJ is packed shock-proof.